Have a deep view into what people are curious about.

🔗 Internet 🔗 Computing 🔗 Antarctica

.aq is the Internet country code top-level domain (ccTLD) for Antarctica (itself not a country). It is derived from the French Antarctique and is reserved for organizations that work in Antarctica or promote the Antarctic and Southern Ocean regions. It is administered by Peter Mott of Antarctica Network Information Centre Limited from Christchurch, New Zealand.

.aq domain names are available free of charge, and registration is granted for a period of 24 months. As a general rule, registrants are only allocated a single .aq domain name. The registry does not have a website. Registration is only possible by contacting Antarctica Network Information Centre Limited.

🔗 Religion 🔗 China 🔗 Visual arts

The Vinegar Tasters (三酸圖; 'three sours'; 嘗醋翁; 'vinegar tasting old-men'; 嘗醋圖, 尝醋图) is a traditional subject in Chinese religious painting. The allegorical composition depicts the three founders of China's major religious and philosophical traditions: Confucianism, Buddhism, and Taoism. The theme in the painting has been interpreted as favoring Taoism and critical of the others.

The three men are dipping their fingers in a vat of vinegar and tasting it; one man reacts with a sour expression, one reacts with a bitter expression, and one reacts with a sweet expression. The three men are Confucius, Buddha, and Laozi, respectively. Each man's expression represents the predominant attitude of his philosophy: Confucianism saw life as sour, in need of rules to correct the degeneration of people; Buddhism saw life as bitter, dominated by pain and suffering due to desires; and Taoism saw life as fundamentally perfect in its natural state. Another interpretation of the painting is that, since the three men are gathered around one vat of vinegar, the "three teachings" are one.

🔗 United States 🔗 Biography 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Lists 🔗 Military history/World War I 🔗 Military history/World War II 🔗 Military history/American Civil War 🔗 Project-independent assessment

The following is a list of Irish-American soldiers, sailors, airmen and Marines who were awarded the American military's highest decoration — the Medal of Honor. The Medal of Honor is bestowed "for conspicuous gallantry and intrepidity at the risk of life, above and beyond the call of duty, in actual combat against an armed enemy force." The medal is awarded by the President of the United States on behalf of the Congress.

Of the 3,464 Medals of Honor awarded as of September 17, 2009, an estimated 2,021 (58%) have been awarded to Irish-American recipients, more than twice the number awarded any other ethnic group; 257 Irish-born Americans have received the Medal of Honor which represents more than half of foreign-born MOH recipients. A monument to these Irish-born Medal of Honor recipients is located at Valley Forge's Medal of Honor Grove; erected by the Ancient Order of Hibernians. The first Irish American to receive the Medal was Michael Madden, who received it for his actions in the American Civil War (Note that the earliest action for which the Medal of Honor was awarded was to Irish American U.S. Army Assistant Surgeon Bernard J.D. Irwin for the engagement at Apache Pass, February 1861. The award was made three decades after the event and after Madden's award).

🔗 Climate change 🔗 Environment 🔗 Meteorology 🔗 Urban studies and planning

An urban heat island (UHI) is an urban area or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak. UHI is most noticeable during the summer and winter. The main cause of the urban heat island effect is from the modification of land surfaces. Waste heat generated by energy usage is a secondary contributor. As a population center grows, it tends to expand its area and increase its average temperature. The term heat island is also used; the term can be used to refer to any area that is relatively hotter than the surrounding, but generally refers to human-disturbed areas.

Monthly rainfall is greater downwind of cities, partially due to the UHI. Increases in heat within urban centers increases the length of growing seasons, and decreases the occurrence of weak tornadoes. The UHI decreases air quality by increasing the production of pollutants such as ozone, and decreases water quality as warmer waters flow into area streams and put stress on their ecosystems.

Not all cities have a distinct urban heat island, and the heat island characteristics depend strongly on the background climate of the area in which the city is located. Mitigation of the urban heat island effect can be accomplished through the use of green roofs and the use of lighter-colored surfaces in urban areas, which reflect more sunlight and absorb less heat.

Concerns have been raised about possible contribution from urban heat islands to global warming. While some lines of research did not detect a significant impact, other studies have concluded that heat islands can have measurable effects on climate phenomena at the global scale.

🔗 Science

In communication theory, the Allen curve is a graphical representation that reveals the exponential drop in frequency of communication between engineers as the distance between them increases. It was discovered by Massachusetts Institute of Technology Professor Thomas J. Allen in the late 1970s.

A related and highly significant finding of Allen's was his identification of the key role of information gatekeepers. Often such interlocutors were poorly recognized by management and yet conveyed vital concepts from just the right people to just the right other people in the organization.

🔗 Computing 🔗 Robotics

The Viterbi algorithm is a dynamic programming algorithm for obtaining the maximum a posteriori probability estimate of the most likely sequence of hidden states—called the Viterbi path—that results in a sequence of observed events, especially in the context of Markov information sources and hidden Markov models (HMM).

The algorithm has found universal application in decoding the convolutional codes used in both CDMA and GSM digital cellular, dial-up modems, satellite, deep-space communications, and 802.11 wireless LANs. It is now also commonly used in speech recognition, speech synthesis, diarization, keyword spotting, computational linguistics, and bioinformatics. For example, in speech-to-text (speech recognition), the acoustic signal is treated as the observed sequence of events, and a string of text is considered to be the "hidden cause" of the acoustic signal. The Viterbi algorithm finds the most likely string of text given the acoustic signal.

🔗 Mathematics 🔗 Statistics

Anscombe's quartet comprises four data sets that have nearly identical simple descriptive statistics, yet have very different distributions and appear very different when graphed. Each dataset consists of eleven (x,y) points. They were constructed in 1973 by the statistician Francis Anscombe to demonstrate both the importance of graphing data when analyzing it, and the effect of outliers and other influential observations on statistical properties. He described the article as being intended to counter the impression among statisticians that "numerical calculations are exact, but graphs are rough."

🔗 Television 🔗 Star Trek

Star Trek: Phase II was the initial working title for what officially became titled Star Trek II, an unproduced American science fiction television series created by Gene Roddenberry as a sequel to (and continuation of) the original Star Trek, which had run from 1966 to 1969. The plans for the series were first developed after several failed attempts to create a feature film based on the property, coupled with plans for a Paramount Television Service (PTS) as a fourth broadcast television network in the United States.

Both PTS and the Star Trek revival were announced in early June 1977, with PTS to debut as one evening of programming each Saturday night and to gradually expand to other nights; a strategy successfully employed by the Fox Broadcasting Company a decade later. Star Trek: Phase II was to be the flagship show, and be broadcast at 8pm EST, followed by a movie of the week starting at 9pm. The initial order was for a two-hour pilot, followed by 13 hour-long episodes.

With the exception of Leonard Nimoy as Mr. Spock, who had ongoing disputes with Roddenberry and Paramount, the entire regular and recurring cast of The Original Series were contracted to return, notably William Shatner as Captain Kirk. Three new and younger regular characters were created, science officer Lt. Xon, navigator Lt. Ilia, and ship's executive officer Willard Decker. Xon, Decker and Ilia were later influential in the development of characters on Star Trek: The Next Generation, and two of the scripts written for Phase II would be re-developed for use in that series.

Behind the cameras, Roddenberry recruited Trek-novices Harold Livingston and Robert Goodwin as producers. Veterans of The Original Series were few, and included costume designer William Ware Theiss and illustrator Mike Minor. Art director Matt Jefferies was otherwise employed and brought in as a "technical advisor" and to update the design of the starship USS Enterprise. Special effects (on set) were to be by Jim Rugg. Science fiction novelist Alan Dean Foster received the assignment to write the story outline for the two-hour pilot, but, with a looming production deadline and unable to find a suitable writer to develop this story into a teleplay, Harold Livingston took on the writing job himself. Of the remaining 12 script assignments handed out, about half were to veterans of The Original Series.

Pre-production began in earnest, with the emphasis on what would be the standing sets of the Enterprise, which differed radically in layout, design and detailing from those for The Original Series. Many costumes and props, too, were designed. Ultimately, Paramount's plans for its network and Star Trek's TV return faltered, as the low anticipated advertising revenues for the Paramount Television Service indicated that it was not viable, and the Paramount Pictures parent company Gulf and Western's chairman, Charles Bluhdorn, refused to back the plan, resulting in the eventual exit of Paramount chief executive officer Barry Diller. In August 1977 Paramount president Michael Eisner announced—internally—that the two-hour pilot script was to be the long sought-after feature film story. However, In order to prevent negative publicity, the "cancellation" of the series and network was not immediately disclosed and development of the series and its scripts continued for a further five months, during which time tests were filmed on the incomplete Enterprise sets in widescreen format - a clear indication that whatever Star Trek would be, it would not be a TV movie.

On March 28, 1978, any illusions that Star Trek would be returning to television were ended when Paramount announced that instead of a series it would be producing what became the big budget film titled Star Trek: The Motion Picture (1979), which was itself a massive reworking of the "In Thy Image" two-hour pilot script.

Preproduction work on the series did not entirely go to waste. The standing Enterprise sets would be extensively reworked for the film (and its eventual sequels), and an unfinished admiral's office set's walls became part of the Enterprise cargo deck. However, the visual effects people hired for the feature film decided that the miniatures under construction were not up to the standards of a post-Star Wars feature, and all were scrapped. Director Robert Collins, who had been hired to direct the pilot, and promised he was to direct the feature, was replaced by Robert Wise.

The concept of a "Paramount Network" led by a flagship Star Trek series finally came to fruition in January 1995 when Paramount launched the United Paramount Network (UPN) and the Star Trek: Voyager series.

🔗 English Language

Hello is a salutation or greeting in the English language. It is first attested in writing from 1826.

🔗 Mathematics

A wallpaper group (or plane symmetry group or plane crystallographic group) is a mathematical classification of a two-dimensional repetitive pattern, based on the symmetries in the pattern. Such patterns occur frequently in architecture and decorative art, especially in textiles and tiles as well as wallpaper.

The simplest wallpaper group, Group p1, applies when there is no symmetry other than the fact that a pattern repeats over regular intervals in two dimensions, as shown in the section on p1 below.

Consider the following examples of patterns with more forms of symmetry:

Examples A and B have the same wallpaper group; it is called p4m in the IUC notation and *442 in the orbifold notation. Example C has a different wallpaper group, called p4g or 4*2 . The fact that A and B have the same wallpaper group means that they have the same symmetries, regardless of details of the designs, whereas C has a different set of symmetries despite any superficial similarities.

The number of symmetry groups depends on the number of dimensions in the patterns. Wallpaper groups apply to the two-dimensional case, intermediate in complexity between the simpler frieze groups and the three-dimensional space groups. Subtle differences may place similar patterns in different groups, while patterns that are very different in style, color, scale or orientation may belong to the same group.

A proof that there were only 17 distinct groups of such planar symmeries was first carried out by Evgraf Fedorov in 1891 and then derived independently by George Pólya in 1924. The proof that the list of wallpaper groups was complete only came after the much harder case of space groups had been done. The seventeen possible wallpaper groups are listed below in § The seventeen groups.